A stereophonic sound indicates a sound having a sense of ambience by reproducing not only a pitch and a tone of the sound but also a direction and a sense of distance, and having additional spatial information by which an audience, who is not located in a space where a sound source is generated, is aware of a sense of direction, a sense of distance, and a sense of space.
When a multi-channel signal, such as from 22.2 channels, is rendered to 5.1 channels, a three-dimensional stereophonic sound can be reproduced by means of a two-dimensional output channel. However, when an elevation angle of an input channel differs from a standard elevation angle and an input signal is rendered using rendering parameters determined according to the standard elevation angle, audio image distortion occurs.